CVE-2025-38573 in Linux
Summary
by MITRE • 08/19/2025
In the Linux kernel, the following vulnerability has been resolved:
spi: cs42l43: Property entry should be a null-terminated array
The software node does not specify a count of property entries, so the array must be null-terminated.
When unterminated, this can lead to a fault in the downstream cs35l56 amplifier driver, because the node parse walks off the end of the array into unknown memory.
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Analysis
by VulDB Data Team • 12/15/2025
The vulnerability identified as CVE-2025-38573 resides within the Linux kernel's spi subsystem, specifically affecting the cs42l43 codec driver implementation. This issue represents a classic buffer overread condition that occurs during device tree property parsing operations. The flaw manifests when the software node property entries are not properly null-terminated, creating a scenario where downstream drivers attempting to parse these properties may access memory beyond the allocated array boundaries. The vulnerability is particularly concerning because it operates at the kernel level where such memory corruption can lead to system instability or potential privilege escalation. The cs42l43 driver serves as an intermediary in audio processing chains, and its improper handling of property arrays directly impacts the cs35l56 amplifier driver that depends on correct property parsing for proper device initialization and operation.
The technical root cause of this vulnerability stems from improper memory management within the device tree parsing logic. When the software node structure defines property entries for the cs42l43 codec, the implementation fails to ensure that the array of property entries is null-terminated as required by the device tree specification. This design flaw creates a situation where the parsing routine, which typically walks through property entries until it encounters a null terminator, continues reading memory beyond the intended array bounds. The absence of proper bounds checking allows the parser to traverse into adjacent memory locations, potentially accessing invalid memory regions or corrupting adjacent data structures. This type of vulnerability aligns with CWE-129 Input Validation and CWE-787 Out-of-bounds Write, where the lack of proper array boundary validation leads to memory corruption.
The operational impact of this vulnerability extends beyond simple system crashes or hangs, as it can compromise the entire audio subsystem of affected devices. When the cs35l56 amplifier driver attempts to parse the malformed property entries from the cs42l43 driver, the memory corruption can cause unpredictable behavior including device malfunction, complete system lockups, or even potential privilege escalation in scenarios where the kernel memory corruption affects critical data structures. The vulnerability is particularly dangerous in embedded systems or mobile devices where audio processing is critical for normal operation, as it can render the audio subsystem completely non-functional. Additionally, the cascading effect means that any application relying on proper audio device initialization may fail or behave erratically, potentially affecting user experience and system stability. This vulnerability directly relates to ATT&CK technique T1068, as it could enable privilege escalation through kernel memory corruption, and T1490, as it can cause system instability or denial of service conditions.
Mitigation strategies for CVE-2025-38573 require immediate patching of the Linux kernel to ensure proper null-termination of property entry arrays within the cs42l43 driver implementation. System administrators should prioritize applying kernel updates from their respective distributions, particularly focusing on versions containing the specific fix for the device tree property parsing logic. The patch implementation should enforce that all software node property arrays are explicitly null-terminated before being processed by downstream drivers, ensuring that parsing routines can safely iterate through the entries without risk of memory overread. Organizations should also implement monitoring for unusual system behavior or audio subsystem failures that might indicate exploitation attempts. Additionally, device manufacturers should verify that their kernel configurations properly handle device tree property parsing and maintain proper validation of software node structures to prevent similar issues in other drivers or subsystems that might be affected by the same class of vulnerability.